JP7635977B2 - Light control device - Google Patents

Description

The present invention relates to smart sunglasses that can adaptively adjust the amount of light for visual hypersensitivity.

Autism spectrum disorder (ASD) is a developmental disorder characterized by poor interpersonal relationships and strong fixations, and is known to have atypical characteristics such as sensory hypersensitivity. Among these, visual hypersensitivity, i.e., glare, is a prominent feature.
Therefore, many people with hypersensitivity symptoms wear sunglasses on a daily basis. However, while ordinary sunglasses are effective in bright places, they become too dark in dark places, and the problem is that they must be removed, which is cumbersome.

In response to this, automatic light-adjusting glasses that can change the transmittance of the entire lens in response to a light sensor are known (see Non-Patent Document 1). According to the automatic light-adjusting glasses of Non-Patent Document 1, an anti-glare effect is obtained in bright places, and the anti-glare effect is suppressed in dark places.
However, in the automatic light-adjusting glasses of Non-Patent Document 1, automatic light adjustment is performed uniformly, so the anti-glare effect is exerted even in relatively dark areas in the field of view, making it difficult to see.

A partial dimming device is known that adjusts light partially rather than uniformly, and includes a liquid crystal panel capable of adjusting light transmittance, a photographing device, and a light transmittance control circuit, extracts high-luminance areas that appear in a scene photographed by the photographing device, and locally reduces the light transmittance of areas on the liquid crystal panel that intersect with the optical path of the high-luminance area using the light transmittance control circuit (see Patent Document 1). The partial dimming device of Patent Document 1 is said to be able to prevent dazzlement of users such as vehicle drivers at night or in tunnels.
However, the partial dimming device of Patent Document 1 has a structure intended for users such as vehicle drivers, and while it can locally reduce the light transmittance of high-brightness areas on the liquid crystal panel to prevent glare from the headlights of oncoming vehicles, it cannot maintain a balance in brightness between the high-brightness areas and other areas, and the areas that are originally high-brightness end up being less bright than the low-brightness areas, resulting in a problem of brightness inversion.
For people with visual hypersensitivity symptoms due to autism spectrum disorders, etc., it is not enough to simply darken bright areas; it is important to maintain a normal balance between light and dark areas.

Also, a device for reducing the light intensity in the field of view of the eyeball or optical instrument is known (see Patent Document 2). The light intensity reducing device of Patent Document 2 includes a power source, a light sensor, a light-transmitting lens, a user control device, and a processing circuit, and the processing circuit processes the generated intensity signal and darkens a specific shutter element among the shutter elements according to the processing result, thereby making it possible to reduce the intensity of light emitted from multiple light sources.
However, the light intensity reduction device of Patent Document 2 also does not display a properly maintained balance between bright and dark areas, and therefore has the problem that it is difficult for people with hypersensitivity to use the device in their daily lives.

Japanese Patent Application Publication No. 8-122736 Special Publication No. 11-507444

Ctrl One smart glasses auto tint to suit lighting conditions Dario Borghino July 02, 2015 (https://newatlas.com/e-tint-ctrl-one-glasses/38259/)

As mentioned above, there have been technologies for adjusting the light transmittance of the liquid crystal panel for high-brightness areas in the field of view. However, users with hypersensitivity to vision have difficulty visually recognizing high-brightness objects, and the conventional technologies do not solve the problem of overcoming these problems and increasing opportunities to go outside.
To make a device easy to use for users with visual sensitivity, that is, to make the device easy to see, it is important that the high-luminance parts are darkened so that they can be viewed comfortably, and that the low-luminance parts are not darkened but maintained in almost the same state, and that the relationship between high and low luminance for each part is not reversed.
In view of the above circumstances, an object of the present invention is to provide a light control device that adjusts high brightness areas to be dark while preventing low brightness areas from becoming dark and preventing the light/dark relationship between each area from being reversed.

To solve the above problems, the light control device of the present invention is a device that adjusts the amount of light incident on the user's eyeball from the outside world, and is equipped with a first transmissive liquid crystal display that is placed in front of the user's eyeball, an image sensor that captures the outside world located in front of the user's eyeball, and a transmittance control means that controls the transmittance of each pixel based on the amount of incident light for each pixel of the image sensor so that the light-dark relationship for each pixel of the first liquid crystal display is not reversed and the amount of light is reduced according to the amount of incident light.

By providing the transmittance control means, it is possible to control the transmittance of each pixel of the first liquid crystal display based on the amount of incident light of each pixel of the image sensor. The fact that the relationship between light and dark is not reversed for each pixel means that the relationship between light and dark is not reversed by controlling the transmittance. By not reversing the relationship between light and dark for each pixel, a more natural display is possible, and users with visual hypersensitivity, etc., can use the display on a daily basis without getting tired, making it comfortable to use.
Reducing the amount of light according to the amount of incident light does not necessarily mean reducing the amount of light in proportion to the amount of incident light. For example, it is possible to control the amount of light to be reduced at the highest rate in the brightest areas, to be reduced slightly in the slightly bright areas, and not to be reduced in the slightly dark areas and dark areas.

In the light control device of the present invention, it is preferable that the transmittance control means keeps the transmittance of pixels of the first liquid crystal display corresponding to pixels with the minimum amount of light or an amount of light below a predetermined threshold value, out of the amount of light incident on each pixel of the image sensor, unchanged or increases the transmittance, and decreases the transmittance of pixels of the first liquid crystal display corresponding to pixels with the maximum amount of light or an amount of light above a predetermined threshold value.
By keeping constant or increasing the transmittance of the pixels of the first liquid crystal display corresponding to the pixels with the minimum light amount or the amount of light below a predetermined threshold among the amount of light incident on each pixel of the image sensor, it is possible to prevent dark areas from becoming darker and improve visibility.In addition, by decreasing the transmittance of the pixels of the first liquid crystal display corresponding to the pixels with the maximum light amount or the amount of light above a predetermined threshold, it is possible to effectively block light from bright areas and improve visibility.

In the light control device of the present invention, it is preferable that the transmittance control means calculates the transmittance using a function that satisfies the following relational expression. By calculating the transmittance using a function that satisfies the following relational expression, a well-balanced display is realized in which the bright parts are adjusted to be dark while the dark parts are unlikely to become dark, and the light-dark relationship for each pixel is not reversed. In the following relational expression, _E1 and _E2 are pixel values of an image of a real environment photographed through the first liquid crystal display in a state in which the first liquid crystal display is controlled to the maximum transmittance, and _E2 > _E1 is satisfied. Furthermore, _E1 ' and _E2 ' are pixel values of an image of a real environment photographed through the first liquid crystal display in a state in which the first liquid crystal display is controlled to the calculated transmittance. Furthermore, ( _E2 '/ _E2 ) = ( _E1 '/ _E1 ) is only partially satisfied. "E2'/E2)<(E1'/E1)" means that, for example, when the pixel values are in the range of 0 to 10000, not all pixel values are controlled to have the same transmittance, but only some pixel values, for example, consecutive pixel values from 100 to 1000, have the same transmittance, and other pixel values satisfy ( _E2 '/ _E2 )<( _E1 '/ _E1 ). Note that there may be multiple consecutive pixel values that satisfy ( _E2 '/ _E2 )=( _E1 '/ _E1 ).

(Equation 1)
(E ₂ ′/E ₂ ) ≦ (E ₁ ′/E ₁ )

The light control device of the present invention may further include an optical system in which a beam splitter is provided in front of the first liquid crystal display, and light from the outside world located in front of the user's eyeball is split by the beam splitter, one of the split light beams enters the user's eyeball via the first liquid crystal display, and the other of the split light beams reaches the image sensor. A half mirror can be used as the beam splitter.
By providing a beam splitter such as a half mirror in front of and outside the first liquid crystal display, branching the optical path of light from the outside world, and providing an image sensor on the branched optical path, the misalignment between the image captured by the image sensor and the image captured by the user's eyeball, which is caused by the misalignment between the image sensor and the eyeball, can be reduced and parallax can be ignored.

In addition, the light control device of the present invention may further include a parallax calibration means for calculating the parallax between the user's eyeball and the image sensor, and calibrating the correspondence between each pixel of the image sensor and each pixel of the first liquid crystal display based on the calculated parallax.
For example, when a beam splitter is not provided in front of the first liquid crystal display and the image sensor is disposed above the position of the user's eyeball, vertical parallax occurs. By providing the parallax calibration means, even if parallax occurs between the image sensor and the eyeball of the user viewing the first liquid crystal display, the correspondence between each pixel of the image sensor and each pixel of the first liquid crystal display can be calibrated, and the amount of light incident on the user's eyeball from the outside world can be adjusted with high precision. The parallax calibration means may be one that performs calibration in real time when the light control device is used, or one that calculates and determines an approximate parallax in advance. The parallax calibration means can calibrate not only up and down, but also left and right, diagonal directions, and front and rear directions.

In the light control device of the present invention, it is preferable that the parallax calibration means further includes a pupil sensor for detecting the pupil position of the user's eye. By including the pupil sensor, the pupil position of the user's eye can be detected, and the parallax can be calibrated with high accuracy based on the detected information.
In the light control device of the present invention, it is preferable that the parallax calibration means further includes a distance sensor capable of calculating a distance between an external object and the first liquid crystal display. By including the distance sensor, it is possible to detect the distance between an external object and the first liquid crystal display, and it becomes possible to calibrate the parallax with high accuracy based on the detected information.

The light control device of the present invention preferably further comprises a second liquid crystal display of a transmissive type arranged in front of the image sensor, and a second transmittance control means for controlling the transmittance of each pixel of the second liquid crystal display.
The provision of the second liquid crystal display makes it easy to grasp the correspondence between each pixel of the image sensor and each pixel of the first liquid crystal display. Furthermore, the provision of the second transmittance control means enables the image sensor to capture high dynamic range images by changing the transmittance of the second liquid crystal display.

The light control device of the present invention preferably comprises an image correcting means for correcting blurring occurring around a portion of the first liquid crystal display where the transmittance is adjusted.
When the first liquid crystal display generates an obscuration mask and adjusts the transmittance, the obscuration mask is generated in front of the outside world seen by the user through the first liquid crystal display, which inevitably results in blurring. By providing an image correction means, such a state can be improved. The image correction means performs an inverse operation (deconvolution) on the portion where blurring occurs. Specifically, a point spread function PSF that generates blurring is estimated, and a pre-corrected image in which the PSF is deconvolved with respect to the target transmittance control image is calculated. By displaying this pre-corrected image on the second liquid crystal display, a pattern close to the target transmittance control image is captured by the image sensor as a result of being influenced by the convolution of the PSF. For the deconvolution, a method using a Wiener filter or a method using machine learning is used. Note that the PSF is different for each pixel or area in the strict sense, so that a pre-corrected image is obtained by pre-correcting each area, interpolating and synthesizing them.

The smart sunglasses of the present invention are provided with any one of the above-mentioned light control devices on the sunglasses body, and a first liquid crystal display is disposed in front of the eyes of the sunglasses body.
The sunglasses body preferably has a structure similar to that of known sunglasses with ear hooks and nose hooks. The structure is such that the light control device is provided so that the first liquid crystal display is located at a position corresponding to the lens part of known sunglasses. With such a structure, it becomes possible for users with visual hypersensitivity to wear the sunglasses on a daily basis and effectively reduce visual irritation.

The light control device of the present invention has the advantage that it can adjust high brightness areas to be darker while preventing low brightness areas from becoming darker and preventing the light-dark relationship between each area from being reversed.

Functional block diagram of a light control device according to a first embodiment FIG. 1 is a schematic diagram of a light control device according to a first embodiment of the present invention. Parallax image Illustrative diagram of occlusion mask generation Image of how the masking mask is generated Graph showing the relationship between the amount of light before and after dimming Image correction diagram Image of the use of the light control device of the first embodiment Functional block diagram of a light control device according to a second embodiment Transmittance control flow chart Functional block diagram of a light control device according to a third embodiment FIG. 13 is a diagram showing the configuration of a light control device according to a third embodiment of the present invention.

Below, an example of an embodiment of the present invention will be described in detail with reference to the drawings. Note that the scope of the present invention is not limited to the following examples and illustrated examples, and many modifications and variations are possible.

Fig. 1 shows a functional block diagram of a light control device of Example 1. As shown in Fig. 1, the light control device 1 includes an image sensor 20, an image correction means 21, transmissive liquid crystal displays (31, 32), a parallax calibration means 40, and a transmittance control means (70, 71). The parallax calibration means 40 includes a distance sensor 50 and a pupil sensor 60.
The image sensor 20 captures an image through the liquid crystal display 32, and thus although there is parallax, it can capture an image similar to the outside world observed by the user's eyeball 11 through the liquid crystal display 31. The transmittance control means 71 can change the transmittance of the liquid crystal display 32 based on the image captured by the image sensor 20. This makes it possible to capture a high dynamic range image.
The parallax calibration means 40 calculates the parallax between the user's eyeball 11 and the image sensor 20, and calibrates the image to be displayed on the liquid crystal display 31 based on the calculated parallax. The distance sensor 50 detects the distance between an external object 8 and the liquid crystal display 31, and the pupil sensor 60 detects the pupil position of the user's eyeball 11.

The transmittance control means 70 controls the liquid crystal display 31 based on the luminance information in the image to adjust the transmittance of the liquid crystal display 31 for each pixel, and can adjust the transmittance by, for example, darkening only the bright parts while leaving the dark parts as they are. Alternatively, it is possible to brighten the more important parts of the field of vision and darken the less important parts.
In this way, the image captured by the image sensor 20 has the parallax between the user's eyeball 11 and the image sensor 20 calibrated by the parallax calibration means 40, and then the transmittance is adjusted for each pixel by the transmittance control means 70 and reflected on the LCD display 31.
The image correction means 21 corrects blurring that occurs around a portion of the liquid crystal display 31 where the transmittance has been adjusted.

Fig. 2 shows a configuration image diagram of the light control device of Example 1. As shown in Fig. 2, the housing 12 of the light control device 1 is provided with a scene camera 2a, a depth camera 5, a pupil detection camera 6, and a liquid crystal display (31, 32). Although not shown here, the housing 12 is further provided with a computer that functions as an image correction means 21, a parallax calibration means 40, and a transmittance control means (70, 71), and is connected to the scene camera 2a, the depth camera 5, the pupil detection camera 6, and the liquid crystal display (31, 32).
The scene camera 2a functions as an image sensor 20. The scene camera 2a and the liquid crystal display 32 are provided in a location close to the user's eyeball 11, such as on the user's forehead, in order to minimize parallax with respect to the user's eyeball 11.

The depth camera 5 is a camera incorporating a depth sensor that acquires depth information, and functions as a distance sensor 50. As the depth camera 5, a known depth camera can be used.
The pupil detection camera 6 functions as a pupil sensor 60. The pupil detection camera 6 detects the pupil position of the user's eyeball 11, and uses this to calculate the vertical parallax between the scene camera 2a and the user's eyeball 11.

3 is a parallax image diagram, in which (1) shows an image captured by a scene camera, and (2) shows a display image seen by a user. In the image, an object 8a is a "Christmas tree," and an object 8b is a "snowman."
In the display image 9b seen from the user's eyeball shown in Fig. 3(2), the position 12a of the object 8a and the position 12b of the object 8b are at approximately the same height. However, in the light control device 1, the scene camera 2a is provided at a position higher than the user's eyeball 11, so in the image 9a captured by the scene camera 2a shown in Fig. 3(1), the position 12b of the object 8b located in the foreground is captured at a slightly lower position than the position 12a of the object 8a.
Such a parallax is calibrated using the parallax calibrating means 40 .

Fig. 4 is an explanatory diagram of the generation of the shielding mask. The light control device 10 shown in Fig. 4 is configured to use an eye camera 2b instead of the user's eyeball 11. The scene camera 2a is provided with a lens 22a and an image detector 23a, and the eye camera 2b is provided with a lens 22b and an image detector 23b.
First, the views of the scene camera 2a and the eye camera 2b are reliably overlapped to generate an accurate occlusion pattern, as shown by arrow 14a. Then, the incident light is blocked by pixel u(u,v) of the liquid crystal display 31, causing point x(x,y) to become dark, as shown by arrow 14b.

5 shows an image of the generation of the occlusion mask, where (1) is an image captured by the scene camera, (2) is a display image seen by the user before the transmittance adjustment, (3) is an occlusion mask image, and (4) is a display image seen by the user after the transmittance adjustment. Note that the occlusion mask refers to the liquid crystal display in a transmittance controlled state, and the display image refers to the state in which the liquid crystal display and the background are superimposed and displayed.
As shown in Fig. 5(1), objects (8a, 8b) are captured in an image 9a captured by a scene camera 2a. Also, as shown in Fig. 5(2), objects (8a, 8b) are displayed in a display image before transmittance adjustment as seen by a user. In both Figs. 5(1) and (2), object 8a is displayed clearly, but object 8b is displayed with a high brightness and is difficult to see. Here, the generation of the occlusion mask will be explained with a focus on these two objects (8a, 8b).

The scene camera 2a photographs through the liquid crystal display 32, thereby being able to photograph an image 9a similar to the outside world observed by the user's eyeball 11 through the liquid crystal display 31. However, as described above, since vertical parallax exists between the scene camera 2a and the user's eyeball 11, the depth camera 5 is used to detect the distance between the liquid crystal display 31 and the object (8a, 8b), the pupil detection camera 6 is used to detect the pupil position of the user's eyeball 11, and the parallax is calibrated in real time using the parallax calibration means 40 based on the distance to the object and the pupil position.
Next, the transmittance control means 70 calculates the brightness of the objects (8a, 8b) in the calibrated image 9a, and generates a shielding mask for adjusting the transmittance according to the brightness of each object. In the shielding mask image 9c shown in FIG. 5(3), the object 8a is shielded in a shape substantially the same as that of the object 8b. In contrast, the object 8a is not shielded. This is based on the transmittance control means 70 determining that the brightness of the object 8a in the image 9a is below a predetermined threshold. In addition, if an object brighter than the object 8a and darker than the object 8b exists in the image, and the brightness of the object is not determined to be below the predetermined threshold, the position of the object is also shielded, but the transmittance is adjusted to be higher than that of the position corresponding to the object 8b.

The occlusion mask shown in the occlusion mask image 9c is superimposed on the real world in the background of the LCD display 31 to produce a display image 9d after transmittance adjustment as seen by the user, shown in FIG. 5(4). As shown in FIG. 5(4), in the display image 9d, the object 8a is displayed as clearly as in the original image, and the object 8b is also displayed clearly due to the application of the occlusion mask.

Here, the shading algorithm will be explained. Figure 6 is a graph showing the relationship between the amount of light before and after dimming, where the vertical axis shows the target amount of light and the horizontal axis shows the original amount of light. The gradient of the response curve represents the transmittance of the liquid crystal.
As shown in Fig. 6, the original image is a straight line with a gradient of 1, and the original light amount and the target light amount are the same. When the original light amount increases, the target light amount also increases similarly. Moreover, linear dimming is a straight line with a gradient of 0.5, and the target light amount is 1/2 (half) of the original light amount. When the original light amount increases, the target light amount increases more slowly than in the original image.
In contrast, in the shading algorithm of the embodiment, when the original light amount increases, the target light amount increases in a parabolic manner. That is, it is tangent to the non-modulation function at the lowest intensity and intersects with the linear modulation function at the highest intensity. The function of the embodiment shown in FIG. 6 draws a parabola in which the slope of the curve is 1 and the transmittance is 1 when the light amount is at the minimum value (0), while the slope of the curve is 0 and the transmittance is 1/2 when the light amount is at the maximum value (4000).

The procedure of the transmittance control will be described. FIG. 10 shows a transmittance control flow diagram. As shown in FIG. 10, first, an image before modulation is captured by the image sensor 20 (step S01). Next, a converted image (=E) is generated by converting the captured image to the viewpoint of the user, taking into account parallax (step S02). The luminance of the converted image is modulated to generate a target image (=E') so as to satisfy the condition of the above-mentioned equation 1 (step S03). The target image is divided by the converted image to calculate the transmittance for each pixel (step S04). An input image to the liquid crystal display 31 to satisfy the calculated transmittance is calculated (step S05). The calculated input image is input to the liquid crystal display 31 (step S06).
In step S05, the relationship between the pixel value and the transmittance of the liquid crystal display 31 is obtained in advance. In this embodiment, the pixel value is measured discretely and approximated by a sigmoid function.

Next, the image correction means will be described. Fig. 7 is an explanatory diagram of image correction, in which (1) shows the masking mask before correction, and (2) shows the masking mask after correction.
When a user views the outside world through the liquid crystal display 31, the liquid crystal display 31 is located in front of the outside world, and therefore the occlusion mask generated by the liquid crystal display 31 has a problem that the contours of the occluded parts are blurred if left as is. That is, as shown in Fig. 7(1) , a rectangular occluded part 15a and a circular occluded part 15b are generated in the occlusion mask image 91 before correction, but when viewed by the user, the contour 16a of the occluded part 15a and the contour 16b of the occluded part 15b are blurred.

Therefore, the image correction means 21 is used to perform correction so that the contour of the occluded part is not blurred when viewed from the user. Specifically, the image correction means 21 estimates a point spread function PSF that causes blurring, and calculates a pre-corrected image by deconvolving the PSF with the target transmittance control image. By displaying this pre-corrected image on the liquid crystal display 32, a pattern close to the target transmittance control image is captured by the image sensor 20 as a result of being influenced by the convolution of the PSF. In this embodiment, a method using a Wiener filter is used for deconvolution. Since the PSF strictly speaking differs for each pixel or area, a pre-corrected image is obtained by pre-correcting each area and interpolating and synthesizing them.
As a result of the correction by the image correction means 21, as shown in FIG. 7B, in the occlusion mask image 92, the contour 16a of the occluded portion 15a and the contour 16b of the occluded portion 15b are both displayed clearly.

8 is a diagram showing an image of the use of the light control device of Example 1, in which (1) is an image captured by a scene camera, (2) is an occlusion mask image, (3) is a display image after transmittance adjustment as seen by a user, and (4) is a display image after transmittance adjustment by linear light control. In both cases, object 8c is a "clay figurine" and object 8d is a "snowman."
As shown in Fig. 8(1), in the image 90a, it is visible that the object 8c is a "clay figurine," but the object 8d is too bright to be identified as a "snowman." As shown in Fig. 8(2), the occlusion mask image 90c is an occlusion mask generated according to the brightness of each part in the image 90a. Here, occlusion masks are generated for both the object 8c and the object 8d, but the occlusion mask is generated so as to reduce the transmittance more for the object 8d than for the object 8c.

In the display image 90e after transmittance adjustment by linear dimming shown in FIG. 8(4), the brightness of the entire display is uniformly dimmed, so that the object 8d can be distinguished as a "snowman." On the other hand, the object 8c is too dark and it is not possible to distinguish that it is a "clay figurine."
In contrast, in the display image 90d after the transmittance adjustment shown in Fig. 8(3), the object 8c can be visually recognized as a "clay figurine," and the object 8d can be visually recognized as a "snowman." In addition, for areas other than the objects (8c, 8d), high-luminance areas are adjusted to be dark, low-luminance areas are not easily darkened, and a display in which the light-dark relationship between each area is not reversed is realized.

In this way, bright areas are extracted from the image captured by the scene camera 2a via the occlusion-disabled LCD display 32, and the bright areas are darkened before being displayed on the occlusion-enabled LCD display 31. The user can view the scene through this occlusion-enabled LCD display 31, allowing them to see an image in which the dark areas remain as they are and the bright areas are darkened by the process.

9 is a functional block diagram of a light control device according to Example 2. As shown in FIG. 9, the light control device 1a includes an image sensor 20, a transmissive liquid crystal display 31, a parallax calibration unit 41, and a transmittance control unit 70.
Unlike the light control device 1 of the first embodiment, the image correction means 21, the liquid crystal display 32, and the transmittance control means 71 are not provided. Moreover, unlike the parallax calibration means 40 of the first embodiment, the parallax calibration means 41 does not perform calibration in real time during use using the distance sensor 50 and the pupil sensor 60, but calculates an approximate parallax from the positions of the image sensor 20 and the user's eyeball 11, and performs a predetermined calibration process in advance from the calculated parallax.
By adopting such a configuration, it is possible to realize a light control device that reduces visual stimulation with a relatively simple configuration.

Figure 11 shows a functional block diagram of the dimming device of Example 3. As shown in Figure 11, dimming device 1b includes a half mirror 4, an image sensor 20, a transmissive liquid crystal display 31, and a transmittance control means 70. Unlike dimming device 1a of Example 2, dimming device 1b includes a half mirror 4 and does not include a parallax calibration means 41.

Fig. 12 shows a configuration image diagram of the light control device of Example 3. The scene camera 2a shown in Fig. 12 functions as an image sensor 20. The scene camera 2a is provided above the user's eyeball 11 here, but depending on the position and direction of the half mirror 4, it can be provided other than above, for example, below. Although not shown, a computer functioning as a transmittance control means 70 is provided in the housing 12a of the light control device 1b, and is connected to the scene camera 2a and the liquid crystal display 31.
Of the incident light from the object 8, the light reflected by the half mirror 4 reaches the scene camera 2a, and the light transmitted through the half mirror 4 reaches the user's eyeball 11. Therefore, after the object 8 is imaged by the scene camera 2a, it is possible to perform transmittance control by the transmittance control means 70 without performing parallax calibration.
By adopting such a configuration, it is possible to realize a light control device that reduces visual stimulation with a configuration simpler than that of the light control device 1a of the second embodiment.

Other Examples
Smart sunglasses may be produced using any of the light control devices (1, 1a, 1b) of Examples 1 to 3. An example of producing smart sunglasses is a configuration in which a pair of light control devices (1, 1a, 1b) is provided so that the liquid crystal displays 31 are arranged at positions corresponding to the left and right lens parts in known sunglasses having ear hooks and nose hooks. Also, among the light control devices (1, 1a, 1b), a configuration in which different light control devices are arranged one on each side may be used. By making smart sunglasses using the light control devices (1, 1a, 1b), users with visual hypersensitivity can wear them daily when going out, and it becomes possible to effectively reduce visual stimuli.

The present invention is useful for smart sunglasses that can be worn by users with visual hypersensitivity and other conditions to reduce visual stimuli.

1, 1a, 1b, 10 Light control device 2a Scene camera 2b Eye camera 4 Half mirror 5 Depth camera 6 Pupil detection camera 8, 8a to 8d Object 9a, 90a Image 9b, 9d, 90d, 90e Display image 9c, 90c, 91, 92 Obstruction mask image 11 Eyeball 12, 12a Housing 13a, 13b Position 14a, 14b Arrow 15a, 15b Obstruction part 16a, 16b Contour 20 Image sensor 21 Image correction means 22a, 22b Lens 23a, 23b Image detector 31, 32 Liquid crystal display 40, 41 Parallax calibration means 50 Distance sensor 60 Pupil sensor 70, 71 Transmittance control means

Claims (8)

A device for adjusting the amount of light incident on a user's eyeball from the outside world,
A first liquid crystal display of a transmissive type arranged in front of the user's eyeball;
An image sensor that captures an image of the outside world located in front of the user's eyeball;
a transmittance control means for controlling the transmittance of each pixel based on the amount of incident light for each pixel of the image sensor so that the light-dark relationship for each pixel of the first liquid crystal display is not reversed and the amount of light is reduced according to the amount of incident light ;
a second liquid crystal display of a transmissive type disposed in front of the image sensor;
a second transmittance control means for controlling the transmittance of each pixel of the second liquid crystal display;
an image correction means for correcting blurring occurring around a portion of the first liquid crystal display where the transmittance is adjusted ;
A light control device comprising: The light control device according to claim 1, characterized in that the transmittance control means keeps the transmittance unchanged or increases the transmittance of pixels of the first liquid crystal display corresponding to pixels of the image sensor with the minimum amount of light or an amount of light below a predetermined threshold, and decreases the transmittance of pixels of the first liquid crystal display corresponding to pixels with the maximum amount of light or an amount of light above a predetermined threshold. 3. The light control device according to claim 1, wherein the transmittance control unit calculates the transmittance using a function that satisfies the following relational expression:
(Equation 1)
(E2'/E2) ≦ (E1'/E1)
(However, E1 and E2 are pixel values of an image of the real environment photographed through the first LCD display with the display controlled to the maximum transmittance, and satisfy E2>E1. Also, E1' and E2' are pixel values of an image of the real environment photographed through the first LCD display with the display controlled to the calculated transmittance, and (E2'/E2)=(E1'/E1) is only partially true.) A beam splitter is provided in front of the first liquid crystal display;
Light from the outside world located in front of the user's eyeball is split by the beam splitter, and one of the split lights is incident on the user's eyeball via a first liquid crystal display,
an optical system through which the other of the split light beams reaches the image sensor;
The light control device according to any one of claims 1 to 3, further comprising: The light control device according to any one of claims 1 to 4, further comprising a parallax calibration means for calculating the parallax between the user's eyeball and the image sensor, and calibrating the correspondence between each pixel of the image sensor and each pixel of the first liquid crystal display based on the calculated parallax. The light control device according to claim 5, characterized in that the parallax calibration means further comprises a pupil sensor that detects the pupil position of the user's eyeball. The light control device according to claim 5 or 6, characterized in that the parallax calibration means further comprises a distance sensor capable of calculating the distance between an external object and the first liquid crystal display. A sunglass body is provided with a light control device according to any one of claims 1 to 7 ,
The smart sunglasses are characterized in that the first liquid crystal display is arranged in front of the eyes of the sunglasses body.